The big question raised by the most important of those smooches is broached at the end of the first act by She (Renee Garvens), an actress who wonders whether they are between a person and person or an actor and an actor.

Sara Ruhl’s comedy is focused on She as she comes back to her career in the theater after a 1o-year absence to focus on her husband (Matthew Byron Cassi) and their daughter (Brittney Thorne). She returns in “The Last Kiss,” a terrible play that was a flop in the ’30s. It reunites her with her ex He (Tyler Keyes). As it happens, they are playing former lovers who reunite, and those two worlds swiftly start bleeding into one another.

Garvens deftly captures She’s shifting emotional landscape, altering her voice when She loses her focus in a scene and begins speaking to He as if they were themselves rather than their characters.

Travis Trevino nearly runs away with the whole show with his handful of sharply rendered moments. In one, he fills in for He in a rehearsal of a kissing scene, serving up one hilariously awkward kiss after another. In another, he has to make the best of things when a performance falls apart.

Director J. Robert Moore and his cast handle the loopier aspects of the play — including a rendition of “Some Enchanted Evening” — well. And the show is a terrific showcase for the gifts of set designer Ryan DeRoos. The first act unfolds as a time lapse of a show coming together, starting with the utilitarian emptiness of the audition space then moving through the evolution of the set from a rough space into a polished design.

“Stage Kiss” can be seen at 8 p.m. Fridays-Saturdays and 3 p.m. Sundays through Feb. 14 at the Cellar Theater of The Playhouse San Antonio, San Pedro Park at Ashby. Tickets range from $12 to $30 at online or by calling 210-733-7258